vise/go/vm/runner.go

412 lines
8.9 KiB
Go

package vm
import (
"context"
"fmt"
"log"
"git.defalsify.org/festive/cache"
"git.defalsify.org/festive/render"
"git.defalsify.org/festive/resource"
"git.defalsify.org/festive/state"
)
type Vm struct {
st *state.State
rs resource.Resource
pg *render.Page
ca cache.Memory
mn *render.Menu
sizer *render.Sizer
}
func NewVm(st *state.State, rs resource.Resource, ca cache.Memory, sizer *render.Sizer) *Vm {
vmi := &Vm{
st: st,
rs: rs,
ca: ca,
pg: render.NewPage(ca, rs),
sizer: sizer,
}
vmi.Reset()
return vmi
}
func(vmi *Vm) Reset() {
vmi.mn = render.NewMenu()
vmi.pg.Reset()
vmi.pg = vmi.pg.WithMenu(vmi.mn) //render.NewPage(vmi.ca, vmi.rs).WithMenu(vmi.mn)
if vmi.sizer != nil {
vmi.pg = vmi.pg.WithSizer(vmi.sizer)
}
}
//type Runner func(instruction []byte, st state.State, rs resource.Resource, ctx context.Context) (state.State, []byte, error)
// Run extracts individual op codes and arguments and executes them.
//
// Each step may update the state.
//
// On error, the remaining instructions will be returned. State will not be rolled back.
func(vm *Vm) Run(b []byte, ctx context.Context) ([]byte, error) {
running := true
for running {
r, err := vm.st.MatchFlag(state.FLAG_TERMINATE, false)
if err != nil {
panic(err)
}
if r {
log.Printf("terminate set! bailing!")
return []byte{}, nil
}
_, err = vm.st.SetFlag(state.FLAG_DIRTY)
if err != nil {
panic(err)
}
op, bb, err := opSplit(b)
if err != nil {
return b, err
}
b = bb
log.Printf("execute code %x (%s) %x", op, OpcodeString[op], b)
log.Printf("state: %v", vm.st)
switch op {
case CATCH:
b, err = vm.RunCatch(b, ctx)
case CROAK:
b, err = vm.RunCroak(b, ctx)
case LOAD:
b, err = vm.RunLoad(b, ctx)
case RELOAD:
b, err = vm.RunReload(b, ctx)
case MAP:
b, err = vm.RunMap(b, ctx)
case MOVE:
b, err = vm.RunMove(b, ctx)
case INCMP:
b, err = vm.RunInCmp(b, ctx)
case MSIZE:
b, err = vm.RunMSize(b, ctx)
case MOUT:
b, err = vm.RunMOut(b, ctx)
case MNEXT:
b, err = vm.RunMNext(b, ctx)
case MPREV:
b, err = vm.RunMPrev(b, ctx)
case HALT:
b, err = vm.RunHalt(b, ctx)
return b, err
default:
err = fmt.Errorf("Unhandled state: %v", op)
}
if err != nil {
return b, err
}
if len(b) == 0 {
b, err = vm.RunDeadCheck(b, ctx)
if err != nil {
return b, err
}
}
if len(b) == 0 {
return []byte{}, nil
}
}
return b, nil
}
// RunDeadCheck determines whether a state of empty bytecode should result in termination.
//
// If there is remaining bytecode, this method is a noop.
//
// If input has not been matched, a default invalid input page should be generated aswell as a possiblity of return to last screen (or exit).
//
// If the termination flag has been set but not yet handled, execution is allowed to terminate.
func(vm *Vm) RunDeadCheck(b []byte, ctx context.Context) ([]byte, error) {
if len(b) > 0 {
return b, nil
}
r, err := vm.st.MatchFlag(state.FLAG_READIN, true)
if err != nil {
panic(err)
}
if r {
log.Printf("Not processing input. Setting terminate")
_, err := vm.st.SetFlag(state.FLAG_TERMINATE)
if err != nil {
panic(err)
}
return b, nil
}
r, err = vm.st.MatchFlag(state.FLAG_TERMINATE, false)
if err != nil {
panic(err)
}
if r {
log.Printf("Terminate found!!")
return b, nil
}
log.Printf("no code remaining but not terminating")
location, _ := vm.st.Where()
if location == "" {
return b, fmt.Errorf("dead runner with no current location")
}
b = NewLine(nil, MOVE, []string{"_catch"}, nil, nil)
return b, nil
}
// RunMap executes the MAP opcode
func(vm *Vm) RunMap(b []byte, ctx context.Context) ([]byte, error) {
sym, b, err := ParseMap(b)
err = vm.pg.Map(sym)
return b, err
}
// RunMap executes the CATCH opcode
func(vm *Vm) RunCatch(b []byte, ctx context.Context) ([]byte, error) {
sym, sig, mode, b, err := ParseCatch(b)
if err != nil {
return b, err
}
r, err := vm.st.MatchFlag(sig, mode)
if err != nil {
return b, err
}
if r {
log.Printf("catch at flag %v, moving to %v", sig, sym) //bitField, d)
vm.st.Down(sym)
b = []byte{}
}
return b, nil
}
// RunMap executes the CROAK opcode
func(vm *Vm) RunCroak(b []byte, ctx context.Context) ([]byte, error) {
sig, mode, b, err := ParseCroak(b)
if err != nil {
return b, err
}
r, err := vm.st.MatchFlag(sig, mode)
if err != nil {
return b, err
}
if r {
log.Printf("croak at flag %v, purging and moving to top", sig)
vm.st.Reset()
vm.pg.Reset()
vm.ca.Reset()
b = []byte{}
}
return []byte{}, nil
}
// RunLoad executes the LOAD opcode
func(vm *Vm) RunLoad(b []byte, ctx context.Context) ([]byte, error) {
sym, sz, b, err := ParseLoad(b)
if err != nil {
return b, err
}
r, err := refresh(sym, vm.rs, ctx)
if err != nil {
return b, err
}
err = vm.ca.Add(sym, r, uint16(sz))
return b, err
}
// RunLoad executes the RELOAD opcode
func(vm *Vm) RunReload(b []byte, ctx context.Context) ([]byte, error) {
sym, b, err := ParseReload(b)
if err != nil {
return b, err
}
r, err := refresh(sym, vm.rs, ctx)
if err != nil {
return b, err
}
vm.ca.Update(sym, r)
if vm.pg != nil {
err := vm.pg.Map(sym)
if err != nil {
return b, err
}
}
return b, nil
}
// RunLoad executes the MOVE opcode
func(vm *Vm) RunMove(b []byte, ctx context.Context) ([]byte, error) {
sym, b, err := ParseMove(b)
if err != nil {
return b, err
}
if sym == "_" {
vm.st.Up()
vm.ca.Pop()
sym, _ = vm.st.Where()
} else {
vm.st.Down(sym)
vm.ca.Push()
}
code, err := vm.rs.GetCode(sym)
if err != nil {
return b, err
}
log.Printf("loaded additional code: %x", code)
b = append(b, code...)
return b, nil
}
// RunIncmp executes the INCMP opcode
func(vm *Vm) RunInCmp(b []byte, ctx context.Context) ([]byte, error) {
sym, target, b, err := ParseInCmp(b)
if err != nil {
return b, err
}
change, err := vm.st.SetFlag(state.FLAG_READIN)
if err != nil {
panic(err)
}
have, err := vm.st.GetFlag(state.FLAG_INMATCH)
if err != nil {
panic(err)
}
if have {
if change {
_, err = vm.st.ResetFlag(state.FLAG_INMATCH)
if err != nil {
panic(err)
}
} else {
return b, nil
}
}
input, err := vm.st.GetInput()
if err != nil {
return b, err
}
log.Printf("sym is %s", sym)
if sym == "*" {
log.Printf("input wildcard match ('%s'), target '%s'", input, target)
} else {
if sym != string(input) {
return b, nil
}
log.Printf("input match for '%s', target '%s'", input, target)
}
_, err = vm.st.SetFlag(state.FLAG_INMATCH)
if err != nil {
panic(err)
}
_, err = vm.st.ResetFlag(state.FLAG_READIN)
if err != nil {
panic(err)
}
target, _, err = applyTarget([]byte(target), vm.st, vm.ca, ctx)
if err != nil {
return b, err
}
code, err := vm.rs.GetCode(target)
if err != nil {
return b, err
}
log.Printf("loaded additional code for target '%s': %x", target, code)
b = append(b, code...)
return b, err
}
// RunHalt executes the HALT opcode
func(vm *Vm) RunHalt(b []byte, ctx context.Context) ([]byte, error) {
var err error
b, err = ParseHalt(b)
if err != nil {
return b, err
}
log.Printf("found HALT, stopping")
return b, err
}
// RunMSize executes the MSIZE opcode
func(vm *Vm) RunMSize(b []byte, ctx context.Context) ([]byte, error) {
log.Printf("WARNING MSIZE not yet implemented")
_, _, b, err := ParseMSize(b)
return b, err
}
// RunMOut executes the MOUT opcode
func(vm *Vm) RunMOut(b []byte, ctx context.Context) ([]byte, error) {
choice, title, b, err := ParseMOut(b)
if err != nil {
return b, err
}
err = vm.mn.Put(choice, title)
return b, err
}
// RunMNext executes the MNEXT opcode
func(vm *Vm) RunMNext(b []byte, ctx context.Context) ([]byte, error) {
selector, display, b, err := ParseMNext(b)
if err != nil {
return b, err
}
cfg := vm.mn.GetBrowseConfig()
cfg.NextSelector = selector
cfg.NextTitle = display
cfg.NextAvailable = true
vm.mn = vm.mn.WithBrowseConfig(cfg)
return b, nil
}
// RunMPrev executes the MPREV opcode
func(vm *Vm) RunMPrev(b []byte, ctx context.Context) ([]byte, error) {
selector, display, b, err := ParseMPrev(b)
if err != nil {
return b, err
}
cfg := vm.mn.GetBrowseConfig()
cfg.PreviousSelector = selector
cfg.PreviousTitle = display
cfg.PreviousAvailable = true
vm.mn = vm.mn.WithBrowseConfig(cfg)
return b, nil
}
func(vm *Vm) Render() (string, error) {
changed, err := vm.st.ResetFlag(state.FLAG_DIRTY)
if err != nil {
panic(err)
}
if !changed {
log.Printf("Render called when not dirty, please investigate.")
}
sym, idx := vm.st.Where()
r, err := vm.pg.Render(sym, idx)
if err != nil {
return "", err
}
vm.Reset()
return r, nil
}
// retrieve data for key
func refresh(key string, rs resource.Resource, ctx context.Context) (string, error) {
fn, err := rs.FuncFor(key)
if err != nil {
return "", err
}
if fn == nil {
return "", fmt.Errorf("no retrieve function for external symbol %v", key)
}
return fn(key, ctx)
}